Steering apparatus

Abstract

Construction is achieved that is capable of maintaining the holding force by which a support bracket 12 a holds an outer column 13 a . One pivoting friction plate 25 for telescopic mechanism is held between the inside surface of a support plate section 20 a of the support bracket 12 a and the outside surface of a displacement bracket 18 a that is fastened to the outer column 13 a . When adjusting the forward-backward position of a steering wheel, the pivoting friction plate 25 for telescopic mechanism pivots around a support pin 33 as an adjustment rod 22 a displaces along a long hole 19 a for telescopic mechanism and a long guide hole 32.

What is claimed is: 
     
       1. A steering apparatus comprising:
 a steering column located around a steering shaft with a steering wheel fastened to a rear end section of the steering shaft, the steering column rotatably supporting the steering shaft; 
 a displacement bracket fastened to a middle section in an axial direction of the steering column; 
 a first through hole formed in a left-right direction in the displacement bracket; 
 a support bracket supported by a vehicle, and having a pair of support plate sections provided on the left side and the right side of the displacement bracket; 
 a plurality of second through holes, each second through hole formed in part of each support plate section of the pair of support plate sections at positions that are aligned with another second through hole; 
 an expansion and contraction apparatus, the apparatus comprising
 an adjustment rod; 
 an adjustment handle provided on a portion of one end section of the adjustment rod, the portion being protruded from one of outside surfaces of the pair of support plate sections; and 
 a pair of pressing sections provided on parts of the adjustment rod at positions on both the left surface side and right surface side of the pair of support plate sections, 
 
 the expansion and contraction apparatus expanding or contracting a space between the pair of pressing sections based on an operation of the adjustment handle; 
 a pivoting friction plate held in at least one of portions located between a pair of surfaces that face each other, which comprise portions located between inside surfaces of the pair of the support plate sections and outside surfaces of the both the left side and the right side of the displacement bracket and between the outside surfaces of the pair of the support plate sections and inside surfaces of the pair of the pressing sections, and having a pivot hole and a long guide hole formed therein at two locations separated from each other; and 
 a support pin provided in part of one of the pair of surfaces holding the pivoting friction plate that is displaced relative to the adjustment rod when performing position adjustment of the steering wheel, or in a portion that does not move with respect to the one of the pair of surfaces, the support pin engaging with the pivot hole, wherein 
 the first through hole is a long hole for telescopic mechanism that extend in the axial direction of the steering column, and the adjustment rod is inserted through the long hole for telescopic mechanism, the second through holes and the long guide hole, 
 when surface pressure at areas of contact between surfaces on both left and right sides of the pivoting friction plate and the pair of surfaces holding the pivoting friction plate is decreased or lost by expanding the space between the pair of pressing sections, and when the adjustment rod is displaced along the long hole for telescopic mechanism, the pivoting friction plate that is held between the at least one of portions between a pair of surfaces pivots around the support pin as the adjustment rod is displaced along the long guide hole, and 
 over entire pivoting range of the pivoting friction plate, a lengthwise direction of the long guide hole or a tangential direction of a portion of the long guide hole where the adjustment rod engages with the long guide hole does not coincide with a lengthwise direction of the long hole for telescopic mechanism. 
 
     
     
       2. The steering apparatus according to  claim 1 , wherein the pivoting friction plate is made of different metallic material in hardness from at least one of a member that comprises the one of the pair of surfaces holding the pivoting friction plate and a member that comprises another surface of the pair of surfaces. 
     
     
       3. The steering apparatus according to  claim 1 , wherein the pivoting friction plate is formed using iron, an iron alloy, aluminum or an aluminum alloy.